bpf/btf: Fix BTF verification of enum members in struct/union

commit da6c7fa upstream.

btf_enum_check_member() was currently sure to recognize the size of
"enum" type members in struct/union as the size of "int" even if
its size was packed.

This patch fixes BTF enum verification to use the correct size
of member in BPF programs.

Fixes: 179cde8 ("bpf: btf: Check members of struct/union")
Signed-off-by: Yoshiki Komachi <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: yosh1k104

kernel/bpf/btf.c

@@ -2309,7 +2309,7 @@ static int btf_enum_check_member(struct btf_verifier_env *env,
 
 	struct_size = struct_type->size;
 	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
-	if (struct_size - bytes_offset < sizeof(int)) {
+	if (struct_size - bytes_offset < member_type->size) {
 		btf_verifier_log_member(env, struct_type, member,
 					"Member exceeds struct_size");
 		return -EINVAL;